Search Results - electronics

A new fully asymmetric backscatter communication protocol where nodes blindly transmit data as and when they sense. This model enables fully flexible node designs, from extraordinarily power efficient backscatter radios that consume barely a few micro-watts to high-throughput radios that can stream at hundreds of Kbps while consuming a paltry tens of micro-watts.

The Frequency-Shifted (FS) Backscatter invention promotes practical backscatter communication for ultra-low power on-body sensors by leveraging radios on existing smart phones and wearables. This invention addresses the self-interference from the wireless carrier without relying on built-in capability to cancel or reject the carrier interference. Utilizing this invention, the tag shifts the carrier signal to an adjacent non-overlapping frequency band and isolates the spectrum of the backscatter signal from the spectrum of the primary signal to enable more robust decoding.

This invention relates generally to a highly optimized low power wearable eye tracker system for detecting eye parameters including eye movement, pupil center, pupil diameter (i.e., dilation), blink duration, and blink frequency. The system operates at a ten-fold reduction in power usage as compared to current eye tracker systems and methods. The invention does not require active calibration by the user. The eye parameters may then be used to determine a variety of physiological and psychological conditions in humans. The eye tracker device includes an imaging component, an illuminator component, a photodiode component and a controller, or special-purpose processor. The controller may be integrated with the eye tracking device or reside remotely such as within another device such as a mobile device including a tablet or smart phone. The system incorporates a neural network enabling trade-offs between power consumption and robustness to illumination conditions, as well as between sensing and computational modes. The system can operate at very high frame rates (exceeding 100 fps) during typical operation.

The invention provides thermoelectric devices similar to conventional Peltier-elements based on folded, multi-layered nanomembranes prepared from 2-dimensional (2D) van der Waals materials. These van der Waals materials (e.g. graphene, hexagonal boron nitride, and transition metal dichalcogenides) have both single atomic layers with strong in-plane covalent bonding and weak bonding across atomic mononolayers. When devices are fabricated by folding monolayers onto themselves and into layered structures (figure). In this configuration, the electric path is shorter and the thermal path is suppressed. Moreover, multiple elements can be combined in series and parallel configurations to produce a useful amount of electricity. Thus, these devices can be used to convert waste-heat into electricity and can also serve a thermoelectric cooler. Some information about different applications here.

It is well appreciated that physical activity is beneficial for health and that long periods of sitting can be detrimental. Individuals use wearable activity trackers to inform themselves of salient data necessary for completion of activity goals (e.g. 10,000 steps per day). However, to date, devices do not provide movement information in context of overall activity patterns, rather they focus on only one metric of behavior. Thus, a user may not fully appreciate how much time they engaged in sedentary behaviors vs. active behaviors during a day or how much overall effort they used.

To address this problem, Dr. Tudor-Locke and her team have devised a simple, dynamic goal driven triangle graphic that display movement and non-movement data in an integrated fashion that can be displayed on wearable devices. Specifically, the arms of the triangle represent step number, effort, and sedentary time. As this information changes throughout the day based on behavior, the triangle will shift in both shape and size. This simple representation will allow the user to visualize their physical activity and exercise in the context of overall activity behavior. The use of simple, intuitive figures that provide individuals with integrated metrics of movement behavior may encourage individuals to make small tweaks in daily behavioral patterns, namely increasing the amount and intensity of physical activity and decreasing sedentary behavior, which could lead to significant health benefits.

Memristive devices are characterized by their present resistance being dependent on the current that last passed through them. In this invention, a memristive RF switch is created by having two micro-electrodes with a small air gap, e.g., 50nm or less, between them. When in the “off” state, the air gap between the electrodes gives the device a very high resistance. When a “setting voltage” is applied between the electrodes, a conductive filament is self-created from one electrode, which bridges the air gap and contacts the other electrode. The device in now the “on” state, and resistance is very low. To turn the device off again, a “resetting voltage” having opposite polarity is applied, and the conductive filament’s connection to the other electrode is broken.

A new low power resistance random access memory (RRAM) device based on silicon materials has been invented. RRAM devices are non-volatile memory devicesas well as promising candidates to replace FLASH memory and become the front runner among non-volatile memories. Instead of charge storage, RRAM uses high and low resistance as state variables. RRAM devices are attractive due to their fast switch speed, overwrite ability without erase, low power consumption, high endurance and long retention times. However, RRAM devices with low programming voltages and excellent device-to-device performance repeatability are still yet to be implemented. The current invention addresses these issues. Moreover, unlike other RRAM devices currently under development, these devices use only silicon-based materials making them compatible with CMOS technology. Altogether, these improvements make this new RRAM device an attractive option for commercial development.

A number of modifications to the geometry of a conventional Balanced Antipodal Vivaldi Antenna (cBAVA) were made to improve performance. This design also incorporates modular construction to improve manufacturability and facilitate replacement of defective portions of the phased array.